However, the key capability being sought by Earth-i is frequent re-visits to locations.

Detecting changes in near real-time is expected to be a burgeoning market for space data and this is only possible when you have a train of spacecraft constantly passing overhead.

At the moment, Earth-i’s plan is to put up additional batches of five spacecraft every year or so after the initial quintet have been launched at the end of 2019.

With a 15-satellite constellation, Earth-i could image a particular place at least three times a day, cloud permitting.

Networks of satellites are all the vogue at the moment.

Indeed, on Friday’s PSLV flight there were two other fascinating demonstrators that will trial technologies for future space constellations.

One of these, the Phase 1 LEO satellite, was also manufactured by SSTL in Britain. It is a prototype for more than 100 follow-on platforms that Telesat of Canada wants to launch to deliver broadband across the globe.

The other PSLV passenger of note in this context was a small radar-imaging satellite for Finnish start-up ICEYE.

Image copyrightICEYEImage caption COTS components significantly reduce the size of the satellite… and its cost

What all these proposed constellations have in common is that they are exploiting the use of cheap electronics normally found in consumer products – rather than the expensive, “space qualified” parts built into traditional spacecraft designs.

This makes the manufacture and launch of multiple platforms much more affordable.

“And the change comes both in cost and in size because COTS components have been miniaturised to fit inside your phone, literally. We are using the same components.”

Friday’s PSLV launch was the first since the rocket failed to jettison its nose cone on an ascent to orbit last August. The navigation satellite being carried on that occasion was lost because it could not get off the vehicle.

The PSLV is India’s workhorse rocket, so the country will be delighted to have it back in action. Its primary payload for the latest flight was another imaging and mapping spacecraft in the nation’s long-running Cartosat series.